<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>Bootstrap 101 Template</title>

    <!-- Bootstrap -->
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" rel="stylesheet">

    <!-- HTML5 shim 和 Respond.js 是为了让 IE8 支持 HTML5 元素和媒体查询（media queries）功能 -->
    <!-- 警告：通过 file:// 协议（就是直接将 html 页面拖拽到浏览器中）访问页面时 Respond.js 不起作用 -->
    <!--[if lt IE 9]>
      <script src="https://cdn.jsdelivr.net/npm/html5shiv@3.7.3/dist/html5shiv.min.js"></script>
      <script src="https://cdn.jsdelivr.net/npm/respond.js@1.4.2/dest/respond.min.js"></script>
    <![endif]-->
  </head>
  <body>
         <!-- nav -->
         <nav class="navbar navbar-inverse navbar-fixed-top" >
             <div class="container">
                 <div class="navbar-header">
                    <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#navbar" aria-expanded="true" aria-controls="navbar">
                        <span class="sr-only">Toggle navigation</span>
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                      </button>
                     <a href="#" class="navbar-brand">Project name</a>
                 </div>
                 <div id="navbar" class="navbar-collapse collapse in" aria-expanded="true" >
                    <form class="navbar-form navbar-right">
                      <div class="form-group">
                        <input type="text" placeholder="Email" class="form-control">
                      </div>
                      <div class="form-group">
                        <input type="password" placeholder="Password" class="form-control">
                      </div>
                      <button type="submit" class="btn btn-success">Sign in</button>
                    </form>
                  </div>
             </div>
         </nav>



         <!-- jumbotron -->
         <div class="jumbotron">
            <div class="container">
              <h1>Hello, world!</h1>
              <p>This is a template for a simple marketing or informational website. It includes a large callout called a jumbotron and three supporting pieces of content. Use it as a starting point to create something more unique.</p>
              <p><a class="btn btn-primary btn-lg" href="#" role="button">Learn more »</a></p>
            </div>
          </div>
         <!-- col-md-n -->
         <div class="row">
            <div class="container">
            <div class="col-md-4">
              <h2>Heading</h2>
              <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p>
              <p><a class="btn btn-default" href="#" role="button">View details »</a></p>
            </div>
            <div class="col-md-4">
              <h2>Heading</h2>
              <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p>
              <p><a class="btn btn-default" href="#" role="button">View details »</a></p>
           </div>
            <div class="col-md-4">
              <h2>Heading</h2>
              <p>Donec sed odio dui. Cras justo odio, dapibus ac facilisis in, egestas eget quam. Vestibulum id ligula porta felis euismod semper. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.</p>
              <p><a class="btn btn-default" href="#" role="button">View details »</a></p>
            </div>
        </div>
          </div>
         <!-- <footer> -->
            <footer>
              <div class="container">
                <p>© 2016 Company, Inc.</p>
              </div>
              </footer>
    <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
    <script src="https://cdn.jsdelivr.net/npm/jquery@1.12.4/dist/jquery.min.js"></script>
    <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/js/bootstrap.min.js"></script>
  </body>
</html>